1. Field of the Invention
The present invention relates to a communication terminal and a communication method using the same, and more particularly, to an apparatus and method for detecting High Speed Shared Control Channel (HS-SCCH) of a communication terminal.
2. Description of the Related Art
Recent mobile communication system has been developed as a high-speed, high-quality packet data communication system for providing not only voice service, but also various multimedia services. To this end, the current 3rd Generation Partnership Project (3GPP) supports High Speed Downlink Packet Access (HSDPA) technology. The HSDPA provides a high-speed downlink packet data service which is available at a frequency band which same as that of the existing Wideband Code Division Multiple Access (WCDMA) Release 99 and Release 4. Such a HSDPA applies Adaptive Modulation and Coding (AMC) and Hybrid Automatic Repeat reQuest (HARQ) techniques for the increase of transmission efficiency, and adds a scheduler function to the base station (Node B) to make fast channel adaptation possible.
The channel structure of the HSDPA includes High Speed Downlink Shared CHannel (HS-DSCH), High Speed Physical Downlink Shared CHannel (HS-PDSCH), High Speed Shared Control CHannel (HS-SCCH) and High Speed Dedicated Physical Control Channel (HS-DPCCH). An HS-SCCH is a shared control channel for transmitting control information for demodulation of a HS-PDSCH. That is, a communication terminal recognizes whether the HS-PDSCH will be demodulated, depending on reliability of the result of demodulation of the HS-SCCH. Also, in a communication terminal, reliability of the demodulation result is a decoding reliability of a Viterbi decoder, and is recognized, for example, by a path metric value. In other words, a communication terminal compares the decoding reliability with a given critical value so as to recognize whether to demodulate the HS-PDSCH.